The present invention relates to a retaining structure for earthen formations which employs the principles of cantilever walls and soil reinforced walls, in combination. In its more specific aspects, the invention is concerned with such a structure wherein the cantilever wall is in situ formed concrete and the soil reinforcing wall is comprised of welded wire mats embedded in the earthen formation with ends of the mats secured to the concrete.
Cantilever walls are well-known in the prior art. Such walls typically include a large reinforced concrete buttress which is formed at the foot of the formation to be retained and extends upwardly across the face of the formation. The buttress is generally keyed to the formation and buried so as to resist tipping. Lateral extensions may be formed on the buttress to further resist tipping. Such walls are necessarily of limited load-bearing capacity and, thus, generally find primary use in situations where the wall is of low or moderate height.
Soil reinforced walls are also well-known in the earth retention art. Such walls typically employ wire mats, straps, or ladder-type structures which are embedded within the earthen formation and serve to build a reinforced mass of earth which performs the retaining function. Such walls have also employed concrete faces to prevent sloughing and enhance their architectural appearance. Certain of the soil reinforced walls employing concrete faces have also provided foundations at the foot of the face to aid in supporting the face. These foundations have not, however, performed a significant cantilever function.
U.S. Pat. No. 4,117,686 discloses a soil reinforced wall wherein reinforcing is achieved through means of wire mats, without a concrete face. U.S. Pat. Nos. 4,329,089 and 4,391,557 disclose soil reinforced walls wherein in situ formed concrete faces are formed on the walls and U.S. Pat. No. 4,324,508 shows a soil reinforced wall wherein precast concrete panels are provided at the face of the wall. In the case of the latter patents, however, the concrete walls are not cantilevered. U.S. Pat. No. 1,762,343 discloses a soil reinforced wall with a concrete face wherein the face is provided with a small foundation, but this foundation does not provide a significant cantilever function.